police are still trying to figure out what caused belcher to snap. he and his girlfriend were reportedly arguing after she returned late from a concert. >> it was an individual that did something that he snapped. and -- and that i don't understand. and i probably never will. >> reporter: it's the latest in a string of player suicides. earlier this year, former falcons safety, ray easterling took his life with a gun, so did o.j. murdock. in may, junior seau died after shooting himself in the chest. the family is having his brain studied. they want to know if the suicide was associated to a history of concussion-related injuries. but the chiefs' management says belcher had no history of head injuries. >> he is a player that is not on the concussion list. >> reporter: belcher's jersey hanging in his locker, his teammates say he will not be forgotten. the team announced it will start a foundation for the 3-month-old daughter left behind. as for what happened on the field, the chiefs played their best game of the season. beating the carolina panthers, ear